The shadow home secretary has ruled himself out as a future Conservative party leader.

Oliver Letwin had been regarded as a likely contender as speculation about Iain Duncan Smith's current tenure in the job rose in Westminster.

But in an interview with The Times, Mr Letwin declared the leader of the opposition "a near- impossible job".

His comment came amid talk of possible leadership challenges, stoked by the
publication of an article in the Spectator magazine - edited by Tory MP Boris
Johnson - which suggested time was "running out" for Mr Duncan Smith.

'Massively ambitious'

Mr Letwin told The Times: "I don't want to lead the Conservative Party. I
will never stand for the leadership of the Conservative Party.

"I would very much like to be Home Secretary. I would not mind having a go at
Chancellor.

"I am massively ambitious but not for that particular post."

He said he was not interested in the leadership because he wanted "a life".

The run-up to the Tories' annual conference in Bournemouth has thrown Mr Duncan Smith's leadership into the spotlight.

It's no good us going on about the vulnerable - we need some flesh on the
bones

Kenneth ClarkeTory MP

Former leadership rival Kenneth Clarke accused Mr Duncan Smith of failing to
develop a clear policy agenda, and said his stance on Iraq risked making the
Tories seem "America's poodle".

One-time Foreign Secretary Sir Malcolm Rifkind said the leader had damaged his
party's credibility with his "unquestioning" support for Blair over Iraq,
while ex-minister and London mayoral candidate Steve Norris said his agenda for
modernising the party was "intellectually incoherent".

'Relevant message'

But Mr Letwin gave his backing to Mr Duncan Smith's strategy of devoting the
first part of the Parliament to policy formulation: "We have started producing
a serious analysis of problems for the first time in a decade, rather than
producing a nifty idea and getting rid of it a week or two later."

Mr Clarke said it was time for the party's proposals on key issues to be spelt
out.

In an interview to be broadcast on Saturday on the BBC News 24 One-to-One programme
he said: "The key thing about this conference is the party's got to do something to
make itself seem relevant, to get people interested in it, to make some sort of
impact.

"It's no good us going on about the vulnerable - we need some flesh on the
bones.

"What exactly would we do, not only about the vulnerable and the problem of
the urban poor - which is very serious - but what about the health service, what
about transport, what about foreign policy and so on?"